Method for pressing and laminating a pile fabric



Jan. 28, 1969 R. G. LEvlTcH METHOD FOR FRESSING AND LAMINATING A PILE FABRIC' mvcmon'. ROBERT G. LEV ITCH ATTY.

United States Patent O 3,424,639 METHOD FOR PRESSING AND LAMINATING A PILE FABRIC Robert G. Levitch, Lexington, Va., assignor, by mesne assignments, to Burlington Industries, Inc., Greensboro, N.C., a corporation of Delaware Filed May 12, 1965, Ser. No. 455,260 U.S. Cl. 156-314 Int. Cl. B32b 31/08, 31/12 2 Claims ABSTRACT F THE DISCLGSURE At the present stage of development of the art of producing soft oor coverings a vast shift in the manufacturing procedures and types of fabric is continuing to take place. With the advent of the tufting or sewing of pile yarns into a backing fabric the speed of production has been greatly increased over that heretofore been possible with the well known power looms of the Axminster, velvet and Wilton types. Since the pile material in a tufted fabric is not securely anchored in the backing at the time it passes through the tufting machine, various means for securely anchoring the pile, and at the same time increasing the dimensional stability and resilience of the fabric have been proposed.

Some years ago only a latex coating or backsize was applied to the fabric. At the present time yardage or broad tufted carpeting incorporates a secondary backing secured with an adhesive. The satisfactory results obtained with this product have been the principal reason why mills producing woven goods have been compelled to follow suit by modifying the weaving equipment to produce one-shot or single plane fabrics to which a secondary backing (usually jute) is adhesively applied. It will be understood that the application of the secondary backing to tufted, knitted or woven goods has introduced various complications. The adhesion of the secondary backing must be excellent throughout the fabric. The amount of adhesive material must be kept to a minimum in order to effect very substantial cost savings which can easily run into six figures annually for a larger mill. The degree to which the adhesive is absorbed or taken up by both the primary and secondary backing as well as the pile yarns on the back of the primary backing are also critical. It has been proposed to apply a precoat or backsizing of adhesive material in order to reduce the condition known as fuzzing or pilling of synthetic yarns such as nylon. This may require a two-pass operation in which the precoating compound is applied and the carpet then passed through a drier prior to the application of the second or laminating coat. Other techniques for applying a precoat without drying may also be employed but the important consideration is the requirement of precoating which involves a concept of backsize application different than the requirements for secondary back application. Since driers of this sort are ordinarily 30 feet long the additional cost of equipment and lioor space consumed in the mill are most important considerations in determining the desirability of the precoating procedure. The present invention overcomes the above disadvantages by utilizing in a single pass operation precoating,

ironing and drying steps 'which provide a far more satisfactory end product, greatly reduce the cost and space required for the finishing equipment, and substantially reduce the amount of adhesive needed to obtain a satisfactory bond.

Depending upon the liber or fibers used in the fabric and the amount of pile yarn actually on the back of the fabric before precoating, wide variations in the amount of adhesive required are found to exist. For example, some acrylic fiber picks up -190% of its own weight of the backsize. This is compared to wool which picks up only 70% of its own weight in backsize. The above tig- Yures, of course, vary depend-ing on whether or not the pile yarns are soft twist or hard twist. Naturally, a soft twist yarn picks up more adhesive than a hard twist yarn. The porosity and absorptive properties of the primary backing are also of considerable importance in affecting the amount of adhesive required. A natural fiber primary backing such as jute or cotton will pick up vastly more adhesive than a smooth nonporous synthetic such as polyolelin or other synthetic backings of the type described in Rhodes Patent 3,110,905 which require minimum adhesive. A felt backing on the other hand requires even more than jute.

It will thus be seen that two important factors affecting the backsize requirements are the type of fiber in the pile yarns and the backing as well as the amount and construction of the liber. A third important element in backsize requirements is the amount of pile yarn actually present on the Iback of the base material. In some tufted fabric constructions the ro'ws of stitches are parallel and the number of stitches per inch are relatively great. Furthermore the gauge or lateral distance between rows varies from 02,2 of an inch to 3%; of an inch. Where the fabric is produced on a shifting needle bar machine of the type described in Batty et al. Patent 3,109,395 there is naturally more yarn on the back of the fabric than in the case where the rows are all straight and parallel.

lI have found that proper pressing of the initially formed fabric whether tufted, woven or knitted smooths and fiattens the back of the fabric vso that porosity and other interstices are sealed and the fabric is compressed to the extent that a much more satisfactory bond with the secondary backing material is obtained with less costly adhesive. A precoating application of ladhesive may be desirably used to further enhance this result.

A primary object of the invention, therefore, is to treat the under side of a preliminarily formed pile fabric to smooth the backing by passing the fabric under pressure over a heated drum or cylinder then applying a liquid adhesive and the secondary backing.

A further object of the invention is to iron the back of a pile fabric under pressure and at a temperature in excess of 350, preferably in the range of 375 to 400 F., prior to the application of a secondary backing.

Further objects will be apparent from the specification and drawings in which FIGURE 1 is a schematic diagram showing the treatment of a pile fabric in accordance with the present invention.

The fabric F is shown at the left of FIGURE 1 substantially as it cornes from the tufting machine or loom. Ordinarily it will be rolled onto a large beam for transfer to the finishing station. Alternatively the fabric may be delivered directly from an inspection and burling station to the precoater 5 which comprises an adhesive material 6 contained in a trough`7 and an applicator roll 8 for applying a controlled amount of adhesive 6 to the back of fabric F. The doctor blade 9 provides even distribution of the adhesive. The fabric then is carried over a guide roller 10 which directs the fabric against the periphery of an ironing drum or cylinder 11. The peripheral speed of drum 11 with respect to the linear speed of travel of fabric F is preferably the same, but relative movement with maximum ironing of the fabric may be provided by utilizing differential fabric speed with respect to the periphery of the drum 11. Advantageously the peripheral speed of cylinder 11 may ibe somewhat in excess of the speed with which the fabric `F travels. The surface temperature of the drum 11, preferably on the order of 400 F., is sufficient to dry the fabric and to press both the pile yarn and the precoat into and against the fabric base. A satisfactory temperature range has been found to be 375 to 450 F. but higher temperatures may be permissible if kthe fabric is not burned or scorched. Low temperatures may induce sticking and should be held high enough to avoid this disadvantage. The temperature of the ironing drum 11 is maintained through the medium of a fluid such as oil 12 `circulated through the interior of the drum by means of a pump 13 and oil lines 14 and 15. The heater or furnace 16 may be provided with a suitable burner 17 for maintaining the desired temperature of the oil which circulates through the lines 14 and 15. These lines are connected to the bore of the drum shaft 18 through swivel joints 19 and the drum shaft 18 is journaled in suitable bearings 20 at either end of the drum.

After passing around the periphery o f the drum the ironed fabric travels around combined guide and pressure roll 25 and thence over the final adhesive application station which likewise comprises an applicator roll 26 for transferring adhesive 27 from the trough 28 to the back of the fabric. A doctor blade 29 controls the amount of adhesive remaining on the fabric. The secondary backing F2 is fed from a supply 30 to a position over guide roll 31 where it is applied to the back of fabric F whereupon the laminated fabric passes through a conventional tunnel drier 32.

It will thus be understood that `I have provided a much improved single pass treatment for pile fabric lwhich achieves the advantages of a precoating without the necessity for two drying operations and Awhich also greatly improves the hand and stability of the fabric by reason of the high temperature pressing and drying step. In addition substantial and worthwhile savings with regard to the amount of total adhesive necessary can be achieved.

Having thus described my invention, I claim:

1. The method of treating a pile fabric which comprises the steps of applying an adhesive precoat to the fabric, pressing the back of the pile fabric at a temperature in the range of 350 F. to 450 F., applying a liquid adhesive to the pressed :back of the fabric, applying a secondary backing to the fabric, and drying the combined fabric and secondary backing.

2. The method of treating a pile fabric having a base material, pile yarns projecting on one side of said base material which comprises the steps of applying an adhesive precoat to said base material, pressing the materialand the precoat around the periphery of a heated drum moving at a differential peripheral speed with respect to the base material, applying a final adhesive coating, applying a secondary backing to the fabric and drying the secondary backing.

References Cited UNITED STATES PATENTS 2,009,291 7/1935 iFerguson, et al. 2,510,313 6/1950 Houth et al 28-74 3,044,896 7/1962 Warner 117-64 3,150,023 9/1964 Penman 156-73 3,285,797 11/1966 Harrison, et al 161-67 3,348,992 10/1967 Cochran 161-66 EARL M. BERGIERT, Primary Examiner. 35 R. A. KILLWORTH, Assistant Examiner.

US. Cl. XR. 

